Detection of fracturing events using derivatives of fracturing pressures
US5105659A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1990 |
| Grant date | Apr 21, 1992 |
| Priority date | — |
| Expiry date | Sep 19, 2010 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B49/006
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
In accordance with illustrative embodiments of the present invention, a method of determining fracture behavior from downhole pressure measurements that are made during a hydraulic well fracturing operation includes pumping fracturing fluids at a constant rate under high pressure against a formation to create fractures therein, and obtaining measurements representative of downhole pressures as pumping progresses. The logarithmic derivatives of such pressure measurements are used to determine the type of fracture behavior, as well as the onset of screenout where the fracturing fluid carries a proppant. In-situ stress or closure pressure also can be determined by finding a value thereof which makes a logarithmic net pressure plot have the same slope as the logarithmic plot of the values of the pressure derivatives.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.